Counterboring-tool.



J. G. GERVAIS.

OOUNTERBORING TOOL.

APPLICATION IILED nuns, 1914.

. mgy gm Patented May 26, 1914.

UNITED STATES PATENT OFFICE.

JOSEPH G. GERVAIS, OF DETROIT, MICHIGAN, ASSIGNOR TO NATIONAL TWIST DRILL & TOOL COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

coUN'rEnBoRrNe-Toon Specification of Letters Patent.

Patented May 26, 1914.

To all whom it may concern Be it known that I, JOSEPH G. GnnvAIs, a citizen of the United States of America, residing'at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Counterboring- 'lools, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to tools designed for counter-boring and of that type in which the cutter is centered by a pilot fitting theoriginal bore.

lit is the object of the invention to obtain a construction in which exchangeable cut-- ters may be used with a common shank, and further to obtain a strong coupling connection between the shank and the tool, permitting of quickly attaching and detaching cutters.

In the drawings: Figure 1 is a perspective view of the shank and cutter detached; and ltig. 2 is a longitudinal section showing these parts attached.

\ A is the shank member which may be of any suitable construction for fitting a drill chuck or other operating device. At the end of this shank is a head B milled or otherwise fashioned to form a cross tenon C at the outercnd thereof and having the pintlc l) projecting concentric with the axis of the shank.

E is the tool which is formed with a mortise F extending across the inner end thereof, and a bore G corresponding in diameter .1') the pintle D. The outer end of this tool is fashioned to form a reamer ll, having end milling cutters l.

J is an exchangeable pilot member having its head K corresponding in diameter to the original bore which is to be enlarged by counter-boring. The member J is also provided with a shank L fitting the bore (l in the cutter and secured in position by a set screw M extending in through the side of the cutter. A second set screw N secures the cutter to the pintle lD.

With the construction as described in use, any one of a series of cutters lfl may be engaged with the shank by slipping on to the pintel I) and inserting the'tenon G into the mortise F. The set screw N is then tightened and will hold the parts from disengagement. The pilot J may be selected with reference to the size of the original bore, and independent of the selection of a particular cutter used for a counter-bore. All that is necessary in exchanging cutters is to loosen the set screw N, while the pilots may be exchanged with equal facility. i

What I claim as my invention is,--

1.. the combination with a rotatable shank member, of an exchangeable cutter member mountable thereon, with a transversely-extending mortise and tenon engagement, and a pin on one of said members engaging a recess in the other to hold the same in axial alinement.

2. The combination of a rotatable shank member provided with a transversely-extending tenon at its end and a pin projectin from said tenon axially of said shank, an a removable cutter member having a transversely extending mortise for engaging said tenon and a central recess for engaging said 3. The coi'nbinati'on of a rotatable shank member having a transversely -extending tenon at the end thereof and a pin projecting from said tenon axially of said shank, a cutter member having an axial bore fitting said pin and a transversely-extending mortise for engaging said tenon, and a set screw for clamping said cutter member to said pin.

4. The combination of a rotatable shank member having a head, with a transverselyextending tenon at its end and a pin projecting centrally from said tenon, a cutter member centrally bored to fit said pin and transversely mortised to engage said tenon, a pilot member having a shank enga ing the opposite end of said bore and a head fitting the initial bore which is to be counter-bored.

5. The combination of a rotatable shank member having an enlarged head with a transversely-extending tenon at the end thereof and a pinlle projecting centrally therefrom, a cutter member axially bored to fit. said pintle and transversely mortised to it said tenon, a pilot having asliank for fitting said bore and an enlarged head, and set screws for clamping the shank to said pilot and said pintle to hold the parts from displacement.

6. The combination of a rotatable shank cutter, and means for securing said cutter member having an enlarged head, of a transand said pilot in osition. 10 versely-extendmg tenon at the end thereof In testimony w ereof I aflix my signature and a central pintle projecting therefrom, a in presence of two witnesses.

removable cutter member centrally bored to JOSEPH G. GERVAIS. fit said pintle and transversely mortised to Witnesses:

engage said tenon, a removable pilot havin HOWARD L. MCGREGOR,

a shank for engaging the central bore of said HIRAM W. BROADWELL. 

